NAME

first - Yagi-Uda project quick antenna builder

SYNOPSIS

first filename elements f_min f_design f_max f_step diameter

DESCRIPTION

The program first is one of a number of executable programs that forms
part of a set of programs, collectively known as the Yagi-Udaproject ,
which were designed for analysis and optimisation of Yagi-Uda antennas.
first is used to define an antenna quickly, if you are not interested
in analysing a specific design (in which case use input ) but need to
get a design that is half-way reasonable so that it may be optimised.
It is much faster in use (since its not interactive) than input The
design methodology that first is the DL6WU antenna designs, which are
valid for 10 or more elements, although first will calculate for any
number of elements. DL6WU reccomends a folded dipole, but the designs
here are for a simple dipole, since I don’t yet know how to calculate
the self and mutual impedances of folded dipoles.

LIMITATIONS

Filenames, including full path, can’t exceed 90 characters.
Does not take into account the variation of impedance of a dipole with
change in wavelength/diameter of elements.

FILES

filename Yagi description, created by first.
filename.out Binary data file, created by yagi.
filename.dat Performance of antenna, created by output.
filename.gai Gain of antenna, created by output.
The DOS .EXE files as distributed require a 387 maths coprocessor to be
present and will not run without it. A 486, Pentium, and I assume later
processors of this series will run it without any extra hardware.

PLATFORMS

Both DOS and and Unix versions have been built. The DOS version as
distributed requires a 386 PC with a 387 maths coprocessor. The DOS
version is no longer being developed, so the DOS executables included
with the distribution are not upto date with the current source code.

SEEALSO

BUGS

Bugs should be reported to: David Kirkby G8WRB
(david.kirkby@onetel.net). Bugs tend actually to be fixed if they can
be isolated, so it is in your interest to report them in such a way
that they can be easily reproduced.
If the input file is edited manually and done incorrectly, there can be
unpredictable results.
Options are not checked for sensible numbers. A negative length can be
entered!